The use of balloon angioplasty catheters to treat strictures, stenoses, or narrowing of the arterial or venal system within various parts of the human body is well known. In a typical procedure, for example, to dilate a blockage or stenosis in the coronary or other arteries in the body, conventionally a relatively large guiding catheter is inserted into the patients' arterial system in the groin. The guiding catheter is then advanced through the arteries to a location near the patients' heart by the means of a radiopaque marker system. A small guide wire is then inserted within the guiding catheter and advanced to the distal end of the guiding catheter, at which point the wire is extended from the distal end of the guiding catheter and steered to extend through the stenosis in the coronary arteries. Once the distal end of the wire is properly positioned by the surgeon, a balloon angioplasty catheter is then advanced into and through the guiding catheter and over the guide wire until the deflated balloon lays across the stenosis. A working fluid is then pumped through the balloon angioplasty catheter, thereby inflating the balloon and dilating the passage through the stenosis.
After such a dilatation procedure, it is often found desirable to install a stent in the area of the stenosis in order to insure patency of the lumen in the artery. Such a stent is generally delivered to the site using the same path as the prior inserted balloon catheter by insertion into, and threading through the guiding catheter, on the end of an inflatable balloon stent delivery catheter. The expandable stent is collapsed around the deflated balloon of the balloon delivery catheter and the catheter is inserted into the patients' body to the location of the stenosis. When the balloon of the stent delivery catheter is inflated, the stent is plastically deformed to an expanded condition to maintain the passage through the stenosis in a dilated condition. Once the stent is expanded, the balloon is deflated, and the stent delivery catheter is withdrawn from the guiding catheter, leaving the expanded stent in place to preserve the patency of the arterial lumen.
Because such conventional stent delivery catheters have a guide wire lumen which extends the entire length of the catheter, they cannot be inserted to the stenosis site over the guide wire that is used to insert the balloon angioplasty catheter (such guide wires are too short). Therefore, after the stenosis has been dilated by inflation of the balloon, the balloon angioplasty catheter and guide wire must be removed from the guiding catheter and a second guide wire, or exchange guide wire, must be inserted through the guiding catheter and steered to the stenosis location. The exchange guide wire is generally more than twice as long as the stent delivery catheter because it is necessary that the guide wire protrude from the patients' body by the length greater than the length of the stent delivery catheter. This allows the guide wire to be held steady with the physician's hand while the stent delivery catheter is advanced over the guide wire. Once the distal end of the stent delivery catheter has been placed within the area of the dilated stenosis, the balloon of the stent delivery catheter may be inflated, thereby plastically deforming the stent in the region of the dilated stenosis. The balloon of the stent delivery catheter is then deflated, allowing the stent delivery catheter to be withdrawn, leaving the expanded stent in place. The exchange guide wire and the guiding catheter are then withdrawn, thereby completing the operation.
In situations where physicians find it desirable to install a stent after the balloon angioplasty procedure, the need to replace the guide wire with an exchange guide wire is a cumbersome and undesirable requirement. This is due to the fact that it is necessary that the second guide wire be steered through the patients' arterial system until it reaches the location of the original stenosis. Furthermore, the great length of the exchange guide wire that extends outside the patients' body must sometimes extend beyond the sterile area of the surgical table.
Additionally, physicians find that some stenoses are too long for a single stent insertion and more than one stent is required to complete the procedure, requiring a gap between each stent. This gap has been found to be undesirable and a possible location where an additional stenosis may develop. Scaffolding the artery wall from inside the lumen to achieve wide and stable patency is an old concept. Several types of stents (coil, mesh, or cage type and metallic or polymer) have been invented and are in use in experimental and clinical procedures. Early application of a stent after the occurrence of occlusion and/or dissection decreases the need for emergency bypass surgery and the risk for myocardial infarction (MI). Most stents currently available for coronary artery disease or neurovascular or other blood vessel blockages are balloon expandable. Some of them require a protective sheath to avoid dislodgement of the stent from the balloon. Because of their large profile, stent/balloon combinations require larger catheters and accordingly larger adapters and sheaths. To facilitate passage of the balloon through tortuous proximal vessels, stiffer angioplasty guide wires are used.
The device as herein disclosed describes a new and unique stent delivery and deployment system that consists of a guide wire cavity incorporated into the conventional stent but separate from the central tubular cavity. More particularly, this device discloses the capabilities of a stent which can be made to abut, overlap, interlock or otherwise communicate with either side of a stent that has been previously inserted, without removing the guide wire and without the need for a guide wire lumen or catheter to be initially inserted. This is accomplished by removing the balloon angioplasty catheter after deflation from the patient with the initial stent in place without removing the guide wire, then by inserting the guide wire from the proximal end into the guide wire cavity of the second stent and inserting the second balloon angioplasty catheter and stent into the patient as previously described. The stents may be brought together in substantially perfect alignment by means of the guide wire not being removed from the initial stent and the second stent brought to full alignment and engagement with the guide wire captive within the guide wire cavities of both stents, with the results checked by the means of a radiopaque marker system.
The convenience and economy of this device can be described by the ability of maintaining the sterility of the device, not requiring the great length of the exchange guide wire that extends outside the patients' body often required, and the ability of maintaining control of the device during the procedure. Having the guide wire in place, without removal until the procedure is completed, the physician has the ability to verify that the procedure has been completed correctly and negating any reinsertion of either additional guide lumens, guide wires, or balloon catheters into the patient.
U.S. Pat. No. 4,824,435 of Jerry D. Giesy et al. describes an instrument guidance system of elongated flexible elements that are guided into place within a tortuous body passage by providing the elements with annular guides adjacent their distal ends and sliding the elements over a guide wire extended through the passage. The '435 patent describes a guidance system, but does not take into account the use of a stent or the delivery or deployment thereof.
U.S. Pat. No. 5,690,642 of Thomas A. Osborne teaches of a rapid exchange stent delivery balloon catheter, which allows exchange from a balloon angioplasty catheter to a stent delivery catheter without the need to replace the angioplasty catheter guide wire with an exchange-length guide wire before exchanging the stent delivery catheter for the balloon angioplasty catheter. The stent delivery catheter of this invention includes a relatively short guide wire shaft, which is bonded to the catheter shaft only at a location distal to the inflation lumen. Although the '642 patent eliminates the need for the exchange-length guide wire, it provides no means to engage a second stent without removing the angioplasty catheter guide wire and restarting the procedure.
U.S. Pat. No. 6,413,269 of Dennis Bui et al. tells of a stent delivery catheter. The catheter includes an inner tube and an outer tube, which are rotatable relative to each other. The inner catheter and the outer catheter include recesses to receive the ends of the stent, permitting pull wires to engage the stent ends without need for the pull wires to extend radially beyond the bounds of the catheter or requiring the stent ends to protrude into the lumen of the inner or outer catheter. This '269 patent deals with the manipulation of the conventional stent and does not incorporate the unique feature of the guide wire passage as an integral part of the stent structure.
U.S. Pat. No. 5,810,871 of Joel F. Tuckey et al. discloses a stent delivery system comprising an inflation shaft having an expandable balloon sealingly mounted at the distal end thereof and a tubular sheath having the inflation shaft longitudinally running therethrough. The tubular sheath has an expandable sheath at the distal end thereof with the balloon longitudinally running therethrough and an expandable stent mounted on the expandable sheath. This is another patent that is designed specifically for the insertion of a single stent and if a second is required, the procedure must be repeated without the ability of joining the stents together.
U.S. Pat. No. 6,015,429 of Lilip Lau et al. describes a foldable stent or stent-graft, which may be per cutaneously delivered with or on a catheter, typically an endovascular catheter, to a body cavity of lumen and then expanded. The expandable stent structure utilizes torsional members that distribute bending and folding loads is such a way that the stent is not plastically deformed. The '429 patent deals primarily with the structure of the segmented shapes of the stent with the ability of lacing it together prior to insertion. It does not incorporate a guide wire channel and does not describe the overlapping or interlocking capabilities.
U.S. Pat. No. 6,048,361 of Randolf Von Oepen teaches of a device for implanting into a body vessel in the region of a vessel branching has a radially expandable stent formed as a hollow cylindrical element and provided with an increased radial opening. The '361 patent describes a unique design of a stent with an opening on the side to be applied at the juncture of a vessel allowing the blood to flow to the side through the opening. It does not describe a stent with the guide wire passage and the overlapping or interlocking capabilities.
U.S. Pat. No. 6,071,285 of Robert D. Lashinski describes a balloon portion of a balloon catheter for implanting a stent structure that is at least initially retained laterally to a guide wire by passing the guide wire axially along the balloon inside the stent structure but not through the interior of the balloon or any permanent guide wire lumen at the location of the balloon. The '285 patent is another patent designed for the implantation of a single stent whereby if another stint is required the procedure must be repeated due to the fact that the guide wire feeds in and out of the balloon catheter lumen along with the fact that there is no adaptation for the overlapping or interlocking of additional stents.
U.S. Pat. No. 6,270,521 of Robert E. Fischell teaches of a stent delivery system for placing a stent within a stenosis in a vessel of a human body without the need for pre-dilation of the stenosis or post-dilation of the stent. This design makes it possible for the stent delivery catheter to be pushed through even very tight stenosis without requiring pre-dilation. This '521 patent deals with the delivery and application of a single stent with no means of inserting a second without removal of the device and repeating the process, and no means of joining two or more stents in the same operation without removing the guide wire.
U.S. Pat. No. 6,409,754 of Scott R. Smith et al. describes a radially expandable segmented stent having plastic, i.e., permanent deformation, with connectors interlocking each segment. This patent deals with the design and segmentation of a conventional cylindrical stent, not with the incorporation of an additional guide wire cavity or the overlapping or interlocking capabilities of the herein disclosed patent.
U.S. Pat. No. 6,409,761 of G. David Jang discloses another patent with the unique patterns in the fabrication of stents endeavoring to make the stints expandable without shortening the initial length. They do not relate to the delivery system or the engagement of two or more stents together.
U.S. Pat. No. 6,423,092 of Arindam Datta tells of a biodegradable stent that is unique, but does not relate to the so-indesclosed patent.
Consequently there exists a need field of angioplasty, for a stent delivery and deployment system, which will allow physicians to insert a guide wire after which one or more stents with interlocking capabilities may be inserted into a stenosis in the arterial or venal system of the human body.